Therapeutical compositions containing derivatives of, acrylic acid having an oxygen-containing heterocycle, therapeutic treatment therewith and new compounds

ABSTRACT

The present invention relates to therapeutic compositions for the treatment of gastric disorders, said compositions containing a compound of the formula   &lt;IMAGE&gt;   in which R is a mono- or poly-cyclic heterocyclic radical, possibly substituted, containing an oxygen atom, R&#39; is a hydrogen atom or a linear, branched or cyclic alkyl radical, saturated or unsaturated, containing up to 18 carbon atoms, and, either A represents a hydrogen atom and B represents a hydroxyl radical or A and B together form a carbon-carbon double bond, as well as the pharmaceutically acceptable alkaline, alkaline-earth or amine salts thereof.

This application is a continuation-in-part of Ser. No. 572,458, filedJan. 20, 1984, now abandoned.

The present invention relates to therapeutic compositions containingderivatives of acrylic acid having an oxygen-containing heterocycle,therapeutic treatment therewith and new compounds.

The invention has as its object therapeutic compositions containing agastric antisecretory and cytoprotective effective amount of a compoundof formula I: ##STR2## in which R is a mono- or poly-cyclic heterocyclicradical, substituted or unsubstituted, containing an oxygen atom, R' isa hydrogen atom or a linear, branched or cyclic alkyl radical, saturatedor unsaturated, containing up to 18 carbon atoms, and,

either A represents a hydrogen atom and B represents a hydroxyl radical

or A and B together form a carbon-carbon double bond, as well as thepharmaceutically acceptable alkaline, alkaline-earth or amine salts ofcompounds of formula I in which R' represents a hydrogen atom and apharmaceutically acceptable carrier.

By heterocyclic radical, there is to be understood, with the aboveproviso, preferably a furyl, pyranyl, benzofuranyl, isobenzofuranyl,chromanyl, isochromanyl, chromenyl, xanthenyl, phenoxathienyl, oxazolyl,isoxazolyl, furazanyl, phenoxazinyl, thieno(2,3-b)-furanyl2H-furo(3,2-b)-pyranyl, benzoxazolyl or morpholinyl radical.

When the heterocyclic radical is substituted, it preferably bears assubstituents one or more substituents selected from the group consistingof esterified or etherified free hydroxyl radicals in which the ester orether portion contains from 1 to 18 carbon atoms, such as, for instance,the acetoxy radical or the methoxy radical, the ketone and oximefunctions, linear, branched or cyclic saturated or unsaturated alkylradicals having up to 18 carbon atoms, for instance, the methyl, ethyl,propyl or isopropyl radical, the ethenyl radical --CH═CH₂ or the ethynylradical --C.tbd.CH, the halogen atoms, such as fluorine, chlorine andbromine, and the CF₃, SCF₃, OCF₃, NO₂, NH₂ or C.tbd.N groups.

When R' represents an alkyl radical, it is preferably a radicalcontaining from 1 to 5 carbon atoms, for instance, the methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, tertbutyl or n-pentyl radical.

The alkaline or alkaline-earth metal salts of the products of formula I,in which R' represents a hydrogen atom, may be the salts of sodium,potassium, lithium or calcium.

The amine salts of the products of formula I, in which R' represents ahydrogen atom, are the customary amine salts. Among the customaryamines, mention may be made of monoalkylamines, such as, for instance,methylamine, ethylamine, propylamine, the dialkylamines, such as, forinstance, dimethylamine, diethylamine and di-n-propylamine, and thetrialkylamines, such as triethylamine. Mention may also be made ofpiperidine, morpholine, piperazine and pyrrolidine.

The compounds of formula I may exist in various possible stereoisomericforms: the different stereoisomeric forms possible represent, in thecase of the products of formula I in which A and B together represent adouble bond, the E and Z (cis and trans) geometric isomers and, in thecase of products of formula I in which A represents a hydrogen atom andB represents a hydroxy radical, the racemic and optically active formsof these products.

4-(benzofuran-2-yl)-4-oxo-buten-2-oic acid is a known product. It hasbeen described by Aurozo et al, in Chimie Therapeutique 1975, No. 10,page 182 et seq. However, no pharmacological property of this producthas been described up to the present time. In their article, Aurozo etal describe the pharmacological properties of certain products, inparticular the anti-inflammatory and hypercholesterolemizing properties.4-(benzofuran-2-yl)-4-oxo-buten-2-oic acid is one of the products whichare not shown to have interesting pharmacological properties.

As mentioned above, the compositions of the invention containingcompounds of formula I in the different possible stereoisomeric forms,as well as the alkaline, alkaline-earth metal or amine salts of saidproducts of formula I in which R' represents a hydrogen atom, haveinteresting pharmacological properties. In particular, they exhibitextensive anti-ulcer activity. Furthermore, placed in contact with thegastric mucosa, they exhibit gastric antisecretory and cytoprotectiveactivity.

Among the preferred compositions of the invention are those containingcompounds of formula I in which R' represents a hydrogen atom, as wellas their pharmaceutically acceptable alkaline, alkaline-earth or aminesalts, compounds of formula I in which A and B together form acarbon-carbon double bond, as well as the pharmaceutically acceptablealkaline, alkaline-earth or amine salts of these compounds when R'represents a hydrogen atom, and compounds of formula I in which Rrepresents a furyl, pyrannyl, benzofuranyl, oxazolyl or isoxazolylradical, possibly substituted, as well as the pharmaceuticallyacceptable alkaline, alkaline-earth or amine salts of these compoundswhen R' represents a hydrogen atom.

The invention has still more particularly as its object the compositionscontaining the following compounds of formula I:

4-(2-oxo-4-hydroxy-6-methyl-2H-puran-3-yl)-4-oxo-buten-2-oic acid,

trans-4-(2,5-dimethyl-oxazol-4-yl)-4-oxo-buten-2-oic acid,

trans-4-(3,5-dimethyl-isoxazol-4-yl)-4-oxo-buten-2-oic acid,

trans 4-(5-methyl-2-furyl)-4-oxo-2-butenoic acid,

trans 4-(2,5-dimethyl-3-furyl)-4-oxo-2-butenoic acid,

trans 4-(3-furyl)-4-oxo-2-butenoic acid

as well as their pharmaceutically acceptable alkaline, alkaline-earth oramine salts.

The invention, in particular, also has as its object the compositionscontaining 4-(2-furyl)-4-oxo-buten-2-oic acid, as well as itspharmaceutically acceptable alkaline, alkaline-earth or amine salts.

The compositions of the invention are very useful in human therapy, inparticular for the treatment of hyperchlorhydria, gastric andgastroduodenal ulcers, gastritis, hiatal hernia and gastric andgastroduodenal ailments accompanied by gastric hyperacidity.

The dose, which varies in accordance with the compound used and theailment in question, may range, for instance, between 0.5 g and 2 g perday for adults, by mouth.

The above compositions are developed in such a manner as they can beadministered by the digestive or parenteral route.

They may be solid or liquid and be present in the pharmaceutical formscurrently used in human medicine, such as, for instance, simple orcoated tablets, capsules, granules, suppositories and injectablepreparations; they are prepared by the customary methods.

The active compound or compounds may be incorporated in excipientscustomarily employed in these pharmaceutical compositions, such as talc,gum arabic, lactose, starch, magnesium stearate, cocoa butter, aqueousor non-aqueous vehicles, fats of animal or vegetable origin, paraffinderivatives, glycols, various wetting, dispersing or emulsifying agents,and preservatives.

The invention also has as its object a method for the treatment of apatient suffering from hyperchlorhydria, gastric and gastroduodenalulcers, gastrities, hiatus hernia or gastric and gastroduodenal ailmentsaccompanied by gastric hyperacidity, comprising administering to saidpatient a gastric antisecretory and cytoprotective effective amount of acompound of the formula I.

the invention also has as its object new compounds of formula I:##STR3## in which R is a mono- or poly-cyclic heterocyclic radical,possibly substituted, containing an oxygen atom, R' is a hydrogen atomor a linear, branched or cyclic alkyl radical, saturated or unsaturated,containing up to 18 carbon atoms, and,

either A represents a hydrogen atom and B represents a hydroxyl radical

or A and B together form a carbon-carbon double bond, provided that if Aand B together form a carbon-carbon double bond and if R' represents ahydrogen atom, R does not represent a benzofuran-2-yl group, as well asthe pharmaceutically acceptable alkaline, alkaline-earth or amine saltsof compounds of formula I in which R' represents a hydrogen atom.

The products of formula I can be prepared by a process in which there issubjected to the action of glyoxylic acid or of one of its alkyl estersof formula II:

    CHO--CO.sub.2 R'                                           (II)

in which R' is defined as above, a compound of formula III:

    RCOCH.sub.3                                                (III)

in which R retains its previous meaning, in order to obtain a product offormula I_(A) corresponding to a product of formula I, in which Arepresents a hydrogen atom and B represents a hydroxy radical, or aproduct of formula I_(B) corresponding to a product of formula I, inwhich A and B together represent a double bond and, possibly, theproduct of formula I_(A) is subjected to a dehydrating agent in order toobtain the corresponding product of formula I_(B), and, if desired, theproduct of formula I_(A) which has been obtained is resolved into itsoptically active isomers and, if desired, the products of formula Iobtained are salified or esterified in accordance with the customarymethods.

By condensation of a product of formula II and a product of formula III,one obtains, depending on the operating conditions, particularly the pH,temperature and time of heating, a product of formula I_(A) or a productof formula I_(B), or a mixture of these products.

According to the different possible combination of pH, temperature andtime of heating, which are well known to the man skilled in thechemistry of aldolization, one obtains larger or smaller proportions ofproduct I_(A) or product I_(B).

The products of formula I_(A) are always formed first and the productsof formula I_(B) derived therefrom by dehydration.

In general, the proportion of product of formula I_(B), which is formeddirectly, will increase when the operating conditions are such that themedium is more strongly acid (see, for instance, in Mathieu and Allais,Cahiers de Synthese Organique, Vol. 3, page 102, the passage concerningthe chemistry of aldolization).

Under preferred conditions for the carrying out of the invention, theprocess described above is carried out as follows:

When it is desired to directly obtain a product of formula I_(B), thereaction between the product of formula II and the product of formulaIII is carried out in a strongly acid medium. The acid medium may beobtained, for instance, by an excess of glyoxylic acid or by thepresence of an acid, such as acetic acid, hydrochloric acid, sulfuricacid or phosphoric acid, or by the addition of sodium or potassiumbisulfate.

For the direct preparation of product I_(B), one can also operate, forinstance, in the presence of acetic acid at about 130° C., in accordancewith a process similar to that described in Japanese Patent ApplicationNo. 77 39 020 published on October 3, 1977 (C.A. 88, 37442 p) or in J.Med. Chem., 1972, Vol. 15, No. 9, 918-22. Glyoxylic acid may even beused, possibly, in the form of an alkali metal salt, such as the sodiumor potassium salt.

When it is desired to obtain products of formula I_(B), the condensationof the product of formula II with the product of formula III ispreferably carried out at a temperature between 120° and 150° C. andheating is preferably effected for more than three hours.

It is well known that the "aldols" are very easily dehydrated into thecorresponding unsaturated derivatives, either by heating or by treatmentin acid medium, and that is dehydration can be effected either in a fewminutes at high temperature, as described, for instance, in U.S. Pat.No. 3,953,463 (one to two minutes at 155° C.) or at lower temperaturefor a longer period of time.

When it is desired to obtain compounds of formula I_(A), thecondensation of the product of formula II with the product of formulaIII is preferably carried out at a pH greater than 6. This condensationis preferably effected at a temperature below 100° C., and preferably byheating for less than three hours.

When the compound of formula II in which R' represents a hydrogen atomis used, one may also advantageously operate at room temperature in thepresence of a catalyst, such as an alkaline agent (sodium hydroxide,acid sodium carbonate or potassium hydroxide, for instance).

The condensation of the compound of formula II with the compound offormula III can be effected without solvent or in the presence of asolvent, such as an aromatic or aliphatic hydrocarbon (for instance,benzene, toluene or heptane).

The possible dehydration of a compound of formula I_(A) into a compoundof formula I_(B) can be effected, for instance, by heating in acidmedium.

Suitable dehydrating agents can, for instance, be one of theaforementioned acids.

The resolution of the racemic products of formula I into opticallyactive isomers is effected by customary methods.

The alkaline, alkaline-earth or amine salts of compounds of formula Ican be prepared by a customary process, such as, for instance, theaction of corresponding bases on the said products of formula I or bydouble-decomposition or by any customary processes known for this typeof α-β-ethylene carboxylic acids.

The salification reaction is preferably carried out in a solvent or amixture of solvents, such as water, ethyl ether, acetone,tetrahydrofuran or dioxan.

The compounds of formula I, in which R' represents an alkyl radical, canbe prepared by a variant of the above process, in which an alcohol ofthe formula R'OH is reacted with the corresponding acid of formula I,preferably in acid medium. The acid may, for instance, be hydrochloricacid, phosphoric acid or paratoluene sulfonic acid.

The compounds of formula I, in which A and B together form a doublebond, can be prepared by a variant of the previous process by reactingmaleic anhydride with a compound of formula RH, in which R has the samemeaning as previously indicated, in order to obtain the correspondingcompound of formula I in which R' represents a hydrogen atom, which issubjected, if desired, either to the action of a base in order to formthe salt thereof or to the action of an esterification agent in order toobtain a compound of formula I, in which R' represents an alkyl radical.

In one preferred embodiment:

the reaction of the compound of formula RH with maleic anhydride takesplace in the presence of a catalytic amount of aluminum chloride;

the esterification is effected by means of an acid functionalderivative, for instance, the acid anhydride or chloride, or else byreacting the acid and the alcohol in the presence ofdicyclohexylcarbodiimide.

The following examples serve to illustrate the invention without,however, limiting it:

EXAMPLE 1 4-(benzofuran-2-yl)-4-oxo-buten-2-oic acid

6.4 g (0.04 mole) of 2-acetyl benzofuran and 3.68 g (0.04 mole) ofglyoxylic acid monohydrate in 40 cc of glacial acetic acid and heatedfor 28 hours at the boiling point. The mixture is allowed to cool, andthe product which deposits is removed by suction filtration andrecrystallized from ethanol at 95° C., 3.2 g (37.4%) of the expectedproduct are obtained. MP=182°-184° C.

This product is identical to Product 12 described by Alain Aurozo et al,Eur. J. Med. Chem. Chimie Therapeutique, Vol. 10 (1975), page 182 etseq.

EXAMPLE 2 4-(2-oxo-4-hydroxy-6-methyl-2H-pyran-3-yl)-4-oxo-buten-2-oicacid

A suspension of 2.52 g (0.02 mole) of 4-hydroxy-6-methyl-pyran-2-one and6.6 g (0.05 mole) of anhydrous AlCl₃ in 20 cc of dichloroethane istreated with 1.96 g (0.02 mole) of maleic anhydride. The resultantsolution is heated for 6 hours at the boiling point. The reactionmixture is cooled, poured over a mixture of ice and 2N hydrochloricacid, and extracted with ethyl acetate. The organic phase is removed anddried over anhydrous sodium sulfate, filtered and brought to dryness.The residue is recrystallized from ethyl acetate. 1.2 g (26.8%) of theexpected product is obtained. MP=228° C.

    ______________________________________                                        Analysis:                                                                     ______________________________________                                        Calculated:  C %    53.58      H %  3.60                                      Found:              53.8            3.6                                       ______________________________________                                    

EXAMPLE 3 4-(2-furyl)-4-oxo-buten-2-oic acid

A mixture of 4.4 g (0.04 mole) of 2-acetyl furan, 3.68 g (0.04 mole) ofglyoxylic acid monohydrate and 6.72 g (0.08 mole) of sodium bicarbonatein 60 cc of water is kept under agitation for 5 days at roomtemperature. The solution is passed over sulfonic resin to eliminate thesalts and is evaporated to dryness. The oily residue is triturated inacetone. 0.8 g of a white solid is obtained by suction filtration(F=115°-135° C.). By evaporating the filtrate to dryness, one obtains5.3 g (72%) of a clear oil which, in accordance with its NMR spectrum,is compatible with the product ##STR4## 5 g of this oil (0.027 mole) isdissolved in a mixture of 100 cc of glacial acetic acid and 10 cc ofconcentrated hydrochloric acid and heated at 60°-70° C. for 10 hours.The reaction mixture is cooled and brought to dryness and the residuechromatographed over silica by eluting with ethyl ether. By evaporationof the eluate, there are obtained 2.2 g (49%) of the expected product,MP=147°-150° C., which is recrystallized from dilute isopropanol.MP=158°-160° C.

    ______________________________________                                        Analysis:                                                                     ______________________________________                                        Calculated:  C %    57.84      H %  3.64                                      Found:              57.7            3.6                                       ______________________________________                                    

EXAMPLE 4 Trans 4-(2,5-dimethyl-oxazol-4-yl)-4-oxo-buten-2-oic acid

11 g (0.079 mole) of 4-acetyl-2,5-dimethyl oxazol (described in Chem.Ber., 84 96 (1951)) and 9.06 g (0.098 mole) of glyoxylic acidmonohydrate are mixed with 110 cc of glacial acetic acid and kept at theboiling point for 10 hours. The mixture is then cooled, concentrated todryness, taken up in 200 cc of water, acidified by the addition of 2Nhydrochloric acid and left overnight. 4 g of the expected product areobtained upon suction filtration (MP=180°-182° C.) and recrystallizedfrom ethyl acetate with treatment with activated charcoal. 2 g of theexpected product are obtained. MP=183°-185° C.

    ______________________________________                                        Analysis: C.sub.9 H.sub.9 NO.sub.4                                            ______________________________________                                        Calculated: C %    55.38   H %  4.65  N %  7.18                               Found:             55.62        4.58       7.11                               ______________________________________                                    

EXAMPLE 5 Trans-4-(3,5-dimethyl-isoxazol-4-yl)-4-oxo-buten-2-oic acid

3.8 g (0.027 mole) of 4-acetyl-3,5-dimethyl-isoxazole (described in J.Am. Chem. Soc., 97 6489 (1975) and 4.9 g (0.053 mole) of glyoxylic acidmonohydrate are mixed with 60 cc of glacial acetic acid and 6 cc ofconcentrated hydrochloric acid. The mixture is kept at the boiling pointfor 15 hours. It is then cooled and diluted with ice water and thecrystals formed are filtered off, washed with water and dried. 2.2 g ofthe expected product are obtained, which are recrystallized from amixture of benzene and ethyl acetate (3:1). MP=138°-140° C.

    ______________________________________                                        Analysis: C.sub.9 H.sub.9 NO.sub.4                                            ______________________________________                                        Calculated: C %    55.38   H %  4.65  N %  7.18                               Found:             55.33        4.63       6.99                               ______________________________________                                    

EXAMPLE 6 Trans 4-(5-methyl-2-furyl)-4-oxo-2-butenoic Acid

10 g of 2-acetyl 5-methyl furan (J. Am. Chem. Soc., 72 3695 (1950)), 7.4g monohydrated glyoxylic acid and 5 cm³ water are heated to 120°-130° C.for 5 hours, while eliminating the water formed in the course of thereaction. After cooling, 60 cm³ ethyl acetate are added and extractedwith a solution of sodium carbonate. The aqueous phase is acidified,extracted with ethyl acetate, dried, and concentrated to dryness. Theresidue is chromtographed on silica, then, the product is recrystallizedin ethyl acetate. 2.2 g of the expected product are obtained.MP=159°-162° C.

    ______________________________________                                        Analysis: C.sub.9 H.sub.8 O.sub.4 (180.16)                                    ______________________________________                                        Calculated:     C %    60.72    H %  4.70                                     Found:                 60.00         4.48                                     ______________________________________                                    

EXAMPLE 7 Trans 4-(2,5-dimethyl-3-furyl)-4-oxo-2-butenoic Acid

As in Example 1, one starts out with 9 g of 3-acetyl 2.5-dimethylfuran(J. Am. Chem. Soc., 70 739 (1948)), 6 g glyoxylic acid and 6 cm³ water.Following chromatography on silica (eluent: petroleum ether-ethylacetate (2-8), recrystallization in ethyl acetate, 1.8 g of the expectedproduct is obtained. MP=144°-147° C.

    ______________________________________                                        Analysis: C.sub.10 H.sub.10 O.sub.4 (194.19)                                  ______________________________________                                        Calculated       C %    61.93    H %  5.28                                    Found:                  61.85         5.19                                    ______________________________________                                    

EXAMPLE 8 Trans 4-(3-furyl)-4-oxo-2-butenoic Acid 1.5 g of 3-acetylfuran(Nippon Kagaku Zasshi 77 759 (1956)) (C.A. 1958, 348) and 1.25 gmonohydrated glyoxylic acid and 0.5 cm³ water are heated to 100° C. for1 hour and 30 minutes, while eliminating the water formed. The mixtureis poured into a solution of sodium bicarbonate and extracted with ethylacetate the initial product which is not reacted. The aqueous phase isacidified with 10% hydrochloric acid, extracted with ethyl acetate, thendried and concentrated to dryness. The residue obtained ischromatographed on silica, then recrystallized in an ethylacetate/petroleum ether mixture. 280 mg of crystallized product areobtained. MP=104°-106° C.

The latter is dissolved in 6 cm³ of acetic acid containing 0.3 cm³concentrated hydrochloric acid and heated to 60°-70° C. for 1 hour and30 minutes. The residue is evaporated to dryness under reduced pressure,chromatographed on silica, and washed out with an ethylacetate/petroleum ether mixture (2-8).

70 mg of the product are obtained, which crystallizes in ethyl acetate.MP=188°-191° C.

    ______________________________________                                        Analysis: C.sub.8 H.sub.6 O.sub.4 (166.14)                                    ______________________________________                                        Calculated      C %    57.84    H %  3.64                                     Found:                 57.58         3.68                                     ______________________________________                                    

PHARMACEUTICAL FORMS EXAMPLE 9 Tablets

Tablets were prepared in accordance with the following formula:

    ______________________________________                                        Product of Example 3                                                                              100 mg                                                    Excipient q.s. for a finished                                                                     300 mg                                                    tablet to                                                                     Product of Example 6                                                                              100 mg                                                    Excipient q.s. for a finished                                                                     300 mg                                                    tablet                                                                        ______________________________________                                    

(Details of the excipient: lactose, wheat starch, processed starch, ricestarch, magnesium stearate, talc.)

EXAMPLE 10 Capsules

Capsules were prepared in accordance with the following formula:

    ______________________________________                                        Product of Example 3                                                                              100 mg                                                    Excipient q.s. for a finished                                                                     300 mg                                                    capsule to                                                                    Product of Example 7                                                                              100 mg                                                    Excipient q.s. for a finished                                                                     300 mg                                                    capsule                                                                       ______________________________________                                    

(Details of the excipient: talc, magnesium stearate, aerosil.)

PHARMACOLOGICAL STUDY A. Toxicity

The median lethal dose (LD₅₀) was evaluated upon oral administration ofthe products to mice.

The results obtained were as follows:

    ______________________________________                                        Product of Example 1                                                                            LD.sub.50                                                                            350 mg/kg                                            Product of Example 2                                                                            LD.sub.50                                                                            350 mg/kg                                            Product of Example 3                                                                            LD.sub.50                                                                            750 mg/kg                                            Product of Example 4                                                                            LD.sub.50                                                                            350 mg/kg                                            Product of Example 5                                                                            LD.sub.50                                                                            350 mg/kg                                            Product of Example 6                                                                            LD.sub.50                                                                            350 mg/kg                                            Product of Example 7                                                                            LD.sub.50                                                                            350 mg/kg                                            ______________________________________                                    

B. Determination of the gastric antisecretory activity

The technique used is described by H. Shay et al in Gastro. Enterology,5 43 (1945).

Male rats are used of a weight of about 200 g, which had been deprivedof food for 48 hours, but with 8% glucose solution ad libitum. Thepylorus of the rats, which had been slightly anesthetized with ether, isligated and then, upon the end of the operation, the product to betested is administered in different doses or, in the case of the controlanimals, an 0.5% solution of carboxymethyl cellulose is administeredintraduodenally, whereupon the abdominal incision is sutured.

Three hours later, the animals are sacrificed and their stomachs removedafter ligation of the esophagus.

The gastric juice is removed and centrifuged. The volume is then notedand the total acidity is determined on 100 μl of gastric juice bytitration to a pH of 7 by means of 1/100N caustic soda.

The percentages of variation of total acidity of the gastric secretionsare calculated, as compared with the results obtained with the controlanimals.

The results are as follows for a dose of 10 mg/kg:

    ______________________________________                                        Product of Example 1                                                                             53%                                                        Product of Example 2                                                                             70%                                                        Product of Example 3                                                                             94%                                                        Product of Example 4                                                                             77%                                                        Product of Example 5                                                                             87%                                                        Product of Example 6                                                                             75%                                                        Product of Example 7                                                                             45%                                                        ______________________________________                                    

We claim:
 1. A method for the treatment of a patient suffering fromhyperchlorhydria, gastric and gastroduodenal ulcers, gastritis, hiatushernia and gastric and gastroduedenal ailments accompanied by gastrichyperacidity, comprising administering to said patient a gastricantisecretory and cytoprotective effective amount of a compound of theformula ##STR5## in which R is a furyl radical, possibly substituted, R'is a hydrogen atom or a linear, branched or cyclic alkyl radical,saturated or unsaturated, containing up to 18 carbon atoms, and,either Arepresents a hydrogen atom and B represents a hydroxyl radical or A andB together form a carbon-carbon double bond, or a pharmaceuticallyacceptable alkaline, alkaline-earth or amine salt thereof.
 2. A methodaccording to claim 1, wherein the compound is4-(2-furyl)-4-oxo-buten-2-oic acid or a pharmaceutically acceptablealkaline, alkaline-earth or amine salt thereof.
 3. A method for thetreatment of a patient suffering from hyperchlorhydria, gastric andgastroduodenal ulcers, gastritis, hiatus hernia or gastric andgastroduodenal ailments accompanied by gastric hyperacidity, comprisingadministering to said patient a gastric antisecretory and cytoprotectiveeffective amount of trans-4-(5-methyl-2-furyl)-4-oxo-2-butenoic acid ora pharmaceutically acceptable alkaline, alkaline-earth or amine saltthereof.
 4. A method for the treatment of a patient suffering fromhyperchlorhydia, gastric and gastroduodenal ulcers, gastritis, hiatushernia or gastric and gastroduodenal ailments accompanied by gastrichyperacidity, comprising administering to said patient a gastricantisecretory and cytoprotective effective amount oftrans-4-(2,5-dimethyl-3-furyl)-4-oxo-2-butenoic acid or pharmaceuticallyacceptable alkaline, alkaline-earth or amine salt thereof.
 5. A methodfor the treatment of a patient suffering from hyperchlorhydria, gastricand gastroduodenal ulcers, gastritis, hiatus hernia or gastric andgastroduodenal ailments accompanied by gastric hyperacidity, comprisingadministering to said patient a gastric antisecretory and cytoprotectiveeffective amount of trans-4-(3-furyl)-4-oxo-2-butenoic acid or apharmaceutically acceptable alkaline, alkaline-earth or amine saltthereof.